I'm still operating my layout in DC but have purchased my DCC starter set. I've noticed in YouTube videos that the DCC locomotives seem to not have the slow speed control achieved with simple DC. The locomotives seem to start and stop suddenly and slightly unrealistically. Can this be tuned out with momentum or more speed steps?
No offense, but I'd not look at those videos! Clearly people don't have their locos set up right. 99% of the time, the BEMF and PWM of the decoder GREATLY improves the slow speed performance of the locos. can you post one of these videos? I suspect that someone did not set the start speed right, or they used a big "jump" in speed steps in their controller. Even then, with momentum on, it's about impossible to have "jack rabbit" starts on DCC. Greg
Tom, you have a decoder that 'might' be able to start more prototypically, but you may have some work to do with CV changes. Depends on the decoder. For many, CV2 is the place to start. You acquire your current decoder address on the throttle and you assign it the first of at least 28 speed steps. One click on the throttle, whatever. Then, assuming it hasn't begun to move already, you enter programming on the main, or Ops Mode, NOT PAGED or BROADCAST modes, and get into CV2. Assign it a value of about 5 and hit enter. Does the loco begin to crawl? If not, go directly to a value of 10 and hit enter. Do this until the engine begins to creep forward. Now you have an important first step completed, setting V-START so that your decoder assigns the drive the right voltage for the first speed step. NOTE: this will change as your engine both warms up any one session and when it gets more broken-in. You may find, as many of us do, that what works with a cold engine is a bit quick to get the engine underway once it is warmed or more broken-in. Let us assume you have CV2 set reasonably close to what should work. From there, CV3 controls INERTIA and CV4 controls MOMENTUM respectively. From here you acquire each of the two CV's and play with them. Assign a first value near 50 for both and exit programming. With the engine at a full stop, zip your throttle up through about half its possible steps and watch what the engine does. If it takes about 6 seconds to get up to speed, that may be all you want. If you want it looking more like a slow lift, say on a heavy coal drag, maybe you should assign CV3 a value of about 120 and time that. It's subjective, in other words. The Tsunamis, not the eco ones and more recent variants, but the now 10 year old version, need some fiddling up around CV's 185 and 200, or thereabouts, getting the right slow response at ultra-low speeds without having the locomotive jerk to like, or hesitate all the time as it accelerates. I did this about five years ago for a formerly DC BLI Class J 4-8-4 that bucked at low speeds. When I was done, it was like a Swiss engineer had stopped working on his latest Rolex and fiddled with my locomotive.
Cool!!, it good to know that it can be done prototypically and you just told me exactly how to do it!! l really was focused on this as a con of DCC. Can't wait to change over. Thanks guys!
